Conventional artificial lungs include those having a hollow fiber membrane bundle. An example of such an artificial lung is described in Japanese Patent Laid-Open No. Hei 11-47268, corresponding to European Application Publication No. 0 895 786.
This artificial lung includes a housing, a hollow fiber membrane bundle (hollow fiber membrane accumulation) contained in the housing, a blood inflow port and a blood outflow port, and a gas inflow port and a gas outflow port. In the event bubbles are present in the blood flowing in via the blood inflow port of the artificial lung having such a configuration, it is preferable that the bubbles are removed by the hollow fiber membrane bundle.
However, problems arise in that the bubbles are not sufficiently removed by the hollow fiber membrane bundle and might flow out to the blood outflow port together with the blood.